Employed, from c. 1737, by Ernst Ludwig
II, Duke of Sachsen-Gotha and Altenburg, an
amateur astronomer and patron of the arts and
sciences. Twice appealed to Franklin to allow
him to accompany Franklin to the United
States, or to lend him money for that purpose,
so that he might visit his brother Johann
Christoph Hartwig, an itinerant Lutheran
minister (1778, 1783).